A wrench is a tool for applying torque to a threaded fastener, such as a nut, bolt, screw or the like, for the purpose of tightening or loosening the fastener. Ring type wrenches are known and function to engage a fastener and drive or rotate the fastener in a given direction. Typically, conventional ring type wrenches have a ring-shaped head with a curved, usually substantially circular, external surface and a hexagonally shaped internal surface (or other shaped internal surface depending on the application of the wrench). In use, the internal surface or surfaces of the wrench head substantially engage the flat surfaces of the fastener (such as a hexagonally shaped fastener head) to put pressure on the fastener surfaces and corners when the fastener is tightened or loosened.
However, if the nut is undersized, damaged or worn, it is likely that the wrench head will “slip” and rotate around the fastener instead of properly gripping or engaging the flats or corners of the fastener. Ring type wrenches are known that, when a force is exerted on the handle and the fastener resists rotation of the socket or ring, the ring may clamp onto the fastener to limit rotation of the ring or head about the fastener. For example, such ring type wrenches are disclosed in U.S. Pat. No. 7,418,890, which is hereby incorporated herein by reference in its entirety. Typically, such ring type wrenches slip around the fastener unless there is enough resistance to rotation of the head by the fastener to cause the ring or head to clamp around the fastener to limit or substantially preclude relative rotation of the ring or head about the fastener.